Reactivity of Zircaloy-4 with Ti3SiC2 and Ti2AlC in the 1100-1300 °C temperature range

Herein, we report on the interactions between zirconium, in the form of Zircaloy-4 (Zr-4) and the MAX phases, Ti3SiC2 and Ti(2)AIC in the 1100-1300 degrees C range. In both cases, the A-group element, Al or Si, diffused out of the MAX phases and formed intermetallics with the Zr-4. Under comparable conditions, Si penetration into the Zr-4 was roughly an order of magnitude less than that of the Al from the Ti2AlC. The effective diffusion coefficient of85.i.cian be described by D-eff_Si (m(2)/s) = 7.4 x 10(-9)exp(-170 k/mol/RT); that of Al by D-eff_Al (m(2)/s) = 9.3 x 10(-12)exp(-38 kJ/mol/RT). At 38 kJ/mol, the activa ion energy for the Ti2AlC/Zr-4 diffusion bonding process was significantly lower than that of the Ti3SiC2/Zr-4 diffusion couples, at 170 ki/mol. (C) 2015 Elsevier B.V. All rights reserved.